1. Technical Field
The present disclosure relates to a design method of LED freeform surface illumination system, and especially relates to a design method of LED freeform surface illumination system based on XY-polynomial.
2. Description of Related Art
Conventional design methods of LED freeform surface illumination system based on XY-polynomial include obtaining a plurality of data points (including coordinate values and normal vectors) of discrete points on a freeform surface through a differential equation method and surface fitting the plurality of data points by using a least square method. The freeform surface is finally obtained, and a lens comprising the freeform surface is constructed, so establishing an LED freeform surface illumination system. However, the conventional design methods may have a relatively large deviation in the normal vectors, corrupting the uniformity of illumination.